INF 223, Spring 2019, Tentative plan of Lectures (Status 12.02.2019)






Nr.DateWeekTopicsPages





1.15.01.19 3 - What is Category Theory?
- shift of paradigm
- informal discussion of products, dualization, sums
2.18.01.19 3 - graphs and graph homomorphisms: motivation, examples, definition
- opposite graphs
- discussion of isomorhisms between graphs





3.22.01.19 4 - composition of maps and identity maps
- composition of graph homomorphisms and identity graph homomorphisms
- associativity and identity law of composition
- definition of category
- categories Set and Graph
- a universal definition of isomorphism
4.25.01.19 4 - composition of isomorphisms is isomorphism
- isomorphisms in Set are bijective maps
- isomorphisms in Graph are componentwise bijective graph homomorphisms
- some finite categories
- representation of finite categories by pictorial diagrams
- other categories with sets as objects: Incl, Inj, Par
- Nat and Incl as pre-order categories
- pre-order categories and partial order categories





5.29.01.19 5 - subcategory: examples and definition
- discussion associations in class diagrams
- composition of relations
- category Rel
- association ends and multimaps
6.01.02.19 5 - category Mult
- monoids: examples and definition
- monoid morphisms: examples and definition
- category Mon of monoids





7.05.02.19 6 - universal property of lists
- functors: motivation, definition
- functors: examples
- product categories
- opposite category and contravariant functors
- identity functors and composition of functors
- categories of categories: Cat, CAT, SET, GRAPH
8.08.02.19 6 - pathes: motivation, examples, definition
- path graph and evaluation of paths
- categorical diagrams: motivation, definition, examples
- commutative diagram: definition and examples - path categories





9.12.02.19 7 - summary of the first lectures about "structures"
- general discussion about models and metamodels
- discussion of a "metamodel" MG of graphs
- graphs as interpretations of the graph MG in Set
- graph homomorphisms as natural transformations
- definition of natural transformations
10.15.02.19 7 - natural transformations: composition and identities
- definition of interpretation categories
- indexed sets as functor category
- arrow categories
- category of E-graphs
- discussion of arrows between arrows
- path equations, satisfaction of path equations
- model interpretations
- reflexive graphs





11.19.02.19 8 - motivation of "typing" by ER-diagrams and Petri nets
- type graph and typed graphs and their morphisms
- definition slice category
- example typed E-graphs
- indexed vs. typed sets
- equivalence of categories
12.22.02.19 8 - equivalence relations and equivalence classes
- quotient sets and natural maps
- unique factorization of maps
- equivalences as abstraction in mathematics
- representatives and normal forms
- quotient path categories





26.02.19 9 Voluntary lecture Universal Algebra
01.03.19 9 Voluntary lecture Universal Algebra





13.05.03.1910 - monomorphisms: definition, examples in Set, Graph, Incl
- epimorphisms: definition, examples in Set, Graph, Incl
- split mono's and epi's
- in Set all epi's are split -> axiom of choice
14.08.03.1910 - initial objects: definition, examples in , Incl, Set, , Mult, Graph
- terminal objects: definition, examples in , Incl, Set, Mult, Graph





15.12.03.1911 - sum: definition, examples in , Incl, Set, Graph
- product: definition, examples in , Incl, Set, Graph
16.15.03.1911 - motivation pullbacks: intersection, inner join, products of typed graphs
- pullbacks: definition, examples in Incl, Set, Graph
- preimages as pullbacks
- equalizers: definition, example in Set
- kernel and graph of a map f:A->B as equalizers





17.19.03.1912 - general construction of pullbacks by products and equalizers
- fibred products
- equalizers are mono
- monics are reflected by pullbacks, coding of monics by pullbacks
- composition of pullbacks is a pullback and decomposition of pullbacks
18.22.03.1912 - motivation pushouts: sharing, decomposition of graphs, rule applications
- pushouts: definition, examples in , Incl, Set, Graph
- coequalizers, general construction of pushouts by sums and coequalizers
- discussion: two lines of constructions





19.26.03.1913 - definition of diagrams
- cones and limits
- co-cones and colimits
- completeness and co-completeness
- stepwise construction of limits and colimits
20.29.03.1913 - research project: flexible and universal diagrammatic formalism
- categorical sketches: example binary relations
- criticism of sketch approach





21.02.04.1914 - relation = jointly injective/monic
- dualization = jointly surjective/epic (cover), example subclasses
- ER diagrams in DPF
- key = injective map
- composite attributes = products
- formalization of associations: predicate [opp]
22.05.04.1914 - diagrammatic signature: definition and examples
- atomic constraints
- diagrammatic specification
- discussion of two variants of EER models
- semantic interpretations in a "semantic universe" U
- indexed semantics = interpretation categories
- satisfaction of atomic constraints
- specification morphisms: definition and example; category of specifications





09.04.1915 buffer
12.04.1915 buffer





16.04.1916 no lecture (Easter Holiday)
19.04.1816 no lecture (Easter Holiday)





23.04.1917 no lecture (Easter Holiday)
23.26.04.1917 - revised type graph for ER diagrams
- semantics-as-instances
- discussion extending type graphs to metamodels
- informal discussion of modelling hierarchies





30.04.1918 no lecture (Institute Seminar)
24.03.05.1918 - typed signatures, typed atomic constraints, typed specifications
- conformant specification
- modelling formalism and modelling hierarchies





25.07.05.1919 - discussion model transformation
- joined modelling formalism - example object-oriented models joined with relational data models
- transformation rules: definition
- model transformation = application of transformation rule = pushout
- example from oo models to relational data models
- discussion control of rule applications: negative application conditions, stratification
- discussion: extracting the constructed relational data model by pullback
26.10.05.1919 TBA





27.14.05.1920 - course summary
17.05.1920 No lecture (Grunnlovsdag)





21 No more lectures





22 No more lectures





04.06.1923 Oral Exam (Plan)